Anaximander's Book, the Earliest Known Geographical Treatise by William Arthur Heidel.
The School of Miletus: Thales, Anaximander, Anaximenes and Heraclitus by John Marshall.
The Pre-Socratics by George Grote.
The Logic of the Pre-Socratic Philosophy by William Arthur Heidel.
The Eleatics: Xenophanes, Parmenides, Zeno and Melissus by John Marshall.
The Pre-Socratics by Benjamin Cocker.